I have microsoft home and cannot upgrade OS more that 11.7.11.

Hi George,

The good news is that you do not need to buy a new Mac or upgrade your OS to use your purchased Office software. You currently have Microsoft Word for Mac Version 16.77.1 installed, which is the correct and final supported version for your macOS 11.7.11 operating system.

The reason you cannot edit documents right now is simply because your software is not activated, as shown by the "License: Not Activated" status in your first screenshot.

Here is how to fix this and get back to editing:

Activate your existing installation: Open Word, locate the "Activate" or "Sign In" button (usually on the welcome screen or under the "Word" menu at the top), and log in using the Microsoft account associated with your Office purchase (likely the ******@bellsouth.net account shown in your screenshot).

Disable automatic updates: Since your computer cannot be upgraded to macOS 12 or higher, newer versions of Office are incompatible with your system. Open the Microsoft AutoUpdate window from your second screenshot and uncheck the "Automatically keep Microsoft apps up to date" box at the bottom.

Ignore the upgrade errors: Turning off the automatic updates will stop the system from continuously attempting to download incompatible versions and displaying the red "MacOS Upgrade Required" and "Check error" warnings for your apps.

Once you sign in and activate your existing Version 16.77.1 installation, your editing features will unlock and you can continue using Word and Excel normally!

If your version of MacOS is Big Sur (11.7.11), then the error you are seeing is caused by an update on the 13th of July, many people are seeing the exact same error, if you are unable to upgrade your MacOS to a newer compatible version (12 or higher), your Office apps will go into Read Only mode, on the link below they provide full details on that update.

https://support.microsoft.com/office/update-microsoft-365-or-office-on-your-macos-or-ios-device-f418ae5d-bb5f-4078-b3d9-9340f5dd084e

On MacOS Big Sur the previous workaround to install a previous version of Office no longer works after that update, the only option available are to use the free version of Office apps in a web browser.

Microsoft has pulled the plug on older versions of Office and macOS. Here's my article with more details: Most Recent Office You Can Run - Best Practices

As alternatives, you can use Word for the web or Google Docs. Both are "lite" versions that run in a web browser.

For desktop software, take a look at open-source LibreOffice, which has very good compatibility with Office file formats.